Electrical problem - Please HELP!!!!

I have a 99 Suburban 3/4 ton 2wd. A couple of weeks ago I pulled into the driveway, got out and shut the door, and the doors locked by themselves. When I got back in the the radio was locked. I got the code and unlocked the radio. It's been fine until a couple days ago when my wife was driving it and it shut off. It started right back up, everything seemed fine including the radio, she drove to her destination and called me. I went to pick it up and when I got in the radio was locked again. I found some corroded terminals...battery cable, terminal block on the fan shroud, I cleaned them up but could that be it? Computer? Any ideas???

It sounds like you're on the right track. Clean those battery terminals, the battery posts, the post and terminal at the alternator, and the underhood fuseblock. For the battery cables, carefully check for signs of water intrusion into the wiring and corrosiion that's occuring withing the cable. The cables should be fairly flexible. They will be stiff, but will bend when pressure's applied. If they don't there may be corrosion present. After that, provided I didn't find any red flags on the aformentioned items, I'd just keep driving it and keep an eye on it for a while.